Piston-ring.



J. W. FORD.

PISTON RING.

APPLICATION HLED MAY 5, 1916.

l ,Q%7,%9 Patented Nov. 27, 1917..

" TE $1 M i-I ATENT I come W. FORD, OF ST. LOUIS, MISSOURI, ASSIGNOR 0F ONE-THIRD TO TOM I). DAVIS AND ONE-THIRD T0 GEORGE H. ALLAN, OF ST. LOUI$, MISSOURI.

PISTON-RING.

Specification of Letters Patent.

Patented new. av, rat a Application filed May 5, 1916. Serial No. 95,622.

To all whom it may concern:

Be it known that I, JOHN W. Form, a citizen of the United States, and resident of St. Louis, Missouri, have invented certain new and useful Improvements in Piston-Rings, of which the following is a specification containing a full, clear, and exact description, reference being had to the accompanying drawings, forming a part hereof.

My invention relates to piston rings and is especially directed to the composite type, that is, the type of rings having more than one part.

The primary object of my invention is to construct a ring wherein the one part is of a material such as cast iron arranged to bear against the wall of the cylinder, and. the other part arranged to fit within the first mentioned part of cast iron which second mentioned part'is constructed of material preferably spring steel, and having a relatively increased elastic or spring quality over the first mentioned or outer part whereby to produce a ring having a relatively great elastic quality and with a surface of a material not likely to injure the cylinder wall.

A further and more specific object of my invention is to construct a ring of a plurality of parts comprising an outer channeled element the peripheries of the walls of which-channel are concentric with the periphery of the body of the channel thereby forming in effect a concentric packing ring, and which element has the inner periphery of its body portion eccentric to the outer periphery of the body portion, the said element iaving free ends at a point where said body portion is of its least thickness, such channeled eccentric element or part arranged to contain a second part or element constructed of material having a relatively eater elastic or spring quality and whose inner peripheryis eccentric to its outer periphery so that when placed within the first mentioned part or element its inner .periphery will be concentric with the outerfipeect riphery of the other element and in e producing a concentric ring composed of eccentric parts.

With the above purposes in view my invention consists in certain details of construction and arrangement of parts as will be hereinafter fully, clearly and concisely in section embodying my improvements andconstructed in accordance with my invention, the ring being shown in its normal or extended condition; a i

Fig. 2 is an elevation oithe ring contracted or reduced in diameter from its normal condition as when in place between a piston and cylinder;

Fig. 3 is an enlarged transverse sectional elevationtaken on the line 3-3 of Fig. 1;

Fig. 4 is an enlarged transverse sectional elevation taken on the line 4- i of Fig. 1;

Fig. 5 is a sectional elevation taken on the line 55 of Fig. T g I i Fig. 6 is a :Eragmental plan on an enlarged scale showing the lap io'intof the free ends of the outer element of my composite ring in an extended condition;

Fig. 7 is a view similar to Fig. 6 showing the same in a contracted condition as when in use;

Fig. 8 is a plan. on an enlarged scale showing fragments only of the inner and outer elements of my composite ring and the free ends of the inner element extended in their normal position and their relation to a stop pin, and

Fig. 9 is a view similar to Fig. 8 showing the parts in a contracted condition as in use, the stop pin engaging the free ends of the inner element to hold it against rotation relative to the outer element.

Referring by numerals to the accompanying drawings, 10 designates the outer element and 11 the inner element of my composite ring. By preference the outer ring is constructed of cast iron or a material of like quality which is least likely to cut or wear the wall of acylinder.

which 1 ends including substantially onehalf of the body portion for a portion of its length and one of the walls 13 for a portion of its length being cut away leaving a substantially L-shaped endl l, the circumferential boundaries of said ends being substantiallyalong the median line of the ring. This element is preferably made from a cast iron tube as is common, of greater diameter than the cylinder in which itis to be employed, and out after being separated from said tube to produce free ends to permit of its being sprung over the piston and into the cylinder so that it will normally tend to spring outwardly against the cylinder. The said ends 14 are arranged to overlap each other whereby to prevent axial or transverse seams through the ring to prevent the passage of gas or steam from one end of the cylinder to the other.

The inner ring 11 is also preferably constructed from a tube but of a much more elastic material preferably spring steel. This ring is placed in the channel of the outer ring with its free ends diametrically opposite the free ends of the outer ring, its body forming with the body of the outer ring a composite ring of concentric arrangement.

Extended through the body of the ring 10, diametrically opposite its free ends, is a stop pin 15, arranged to engage the free ends of the inner ring so that when in use there can be no rotational movement between the element 10 and element 11, that is, the inner and outer rings are thus held against relative rotational movement.

It will be apparent that by reason of the materials employed in the two elements of my composite ring I have a structure whose outer periphery is of such material as to create a minimum of wear upon the cylinder wall and is of itself possessed of concentric inner and outer peripheral surfaces which at all times prevent spaces between the cylinder and piston to prevent leakage of gas or steam therethrough. It will be further apparent-that the ring or structure carries an element constructed of spring steel or a material having relatively great elastic qualities to bear outwardly against the softer body to hold the said softer body in intimate non-leaking contact with the cylinder wall. Such a ring by reason of the eccentric arrangement of the two bodies entering into its structure is a perfectly balanced ring having like weight at all points circumferentially thereof and is a ring in which the parts of one ring or composite structure are interchangeable with the parts of like other structures that is, the inner element of any one of'my rings will fit the outer element of any other ring of my design, or vice versa.

It is to be particularly noted that the stop pin 15 is located at a point removed from ends as is common, and in thismanner avoids the necessity of shaping saidfree ends to close over a stop pm as is common.

By this expedient also the stop pin is placed at a point where the ring has the greatest body, and for this reasonis least likely to break at the point offthestop.

While I have described the inner element 11 ofmy ring as being constructed of spring steelfor a material possessing greater elasticity than the outer element, 1 do not wish to be understood as limiting myself to spring, steel. The desideratum in the material of the said inner ring is a high carbon steel preferably inter-mingled with nickel, which is highly elastic, either cold or heated as when in use, so that it will have great elasticity during service, the nickeltending to prevent carbon deposits'therein and other corrosion. It will be apparent that it is not practicable to employ such a material nextthe cylinder walls for the reason that due to its hardness it will notreadily conform to uneven or worn cylinder walls but will scratch and produce excessive wear tending to deteriorate the cylinder surface; It is for this reason that I provide such nickel or high carbon steel element with a shoe or outer element having a surface of a material 1 equal in softness or softer than of the cylinder walls.

Having thus described my invention what I claim as new therein and desire to secure the material by Letters-Patent of the United States,

therefor is:

1. A piston ring comprising two elements, one of which consists of wring-like body having its inner periphery eccentric to its outer periphery and having a wall at each side of said body, the outside faces of said walls being of uniform heightsthroughout the circumference of the element and the inside faces of non-uniform heights and a pin secured in the body at a point where neaaeae 5 the body of the ring, the other element consisting of a ring-like body havingits peripheral faces relatively eccentric and whose thickness corresponds with the hei hts of said Walls, so that when the two e ements 10 are united there will be a substantially uniform cross-section throughout, each of said elements having free ends, and means to prevent relative rotation of the elements.

In testimony whereof, I have signed my name to this specification, in presence of 15 two subscribing witnesses.

' JOHN W. FURD. Witnesses:

GEORGE H. ALLAN, Tom D. DAVIS.

Women of this potent may be obtained for flvecenm each, by (addressing the (Hommiamloner of? Fatento,

Wan w i :m in m), a 

